Blowpipe



Aug. 8, 1933. CAMPBELL, JR

BLOWPIPE Filed Aug. 21, 1929 2 Sheets-Sheet 2 character.

giran arras graag -iggjgg BLW'HPE Lorn Campbell, 5r., Lakewood, @hic Application August 21,l929. Serial No. 387,325

This invention 'Z Claims.

relates Ato blowpipes of the character employed for cutting metal with oxygen, and has for its general object to improve the construction and operation of devices of this Among the more limited objects of my invention is to provide a blowpipe of the character described with improved means for controlling the supply of cutting oxygen through the tube leading to the ther object of the blowpipe head. A furinvention is to provide a blowpipe of this character referred to with an improved construction of tip; for forming a leakproof tip and the head also to providemeans connection between a chamber within which the Atip is iitted. Another object of the invention is to provide a novel valve stems which arrangement of valve block and will minimize the risk of fires;

while a still further object of the invention is to simplify and improve the modeof connecting the valve stems and the grips of the valves employed in the valve block.

I accomplish the foregoing through the construction parts shown in the drawings and arrangement of hereof, wherein Fig.

l represents a side elevation and Fig. 2 a plan view of a blowpipe constructed in accordance with my invention; nal section through Fig. 3 a detail in longitudithe valve and the valve mounting for controlling the supply of cutting oxygen, the adjacent tube beingl shown in transverse section of the valve block;

through the blowpipe ends of the cutting-oxygen in elevation; Fig. 4 a detail through therear portion Fig. 5 a detail in section head and tip; and Fig.

6 a detail in section corresponding to the line 6-6 of Fig. 5.

Describing the v acters, A denotes generally a B a tip detachably connected thereto the jointl arious parts by reference charblowpipe head and between said tip and head being suitably sealed by means including a retaining nut C. The combustible gas and oxygen pipe are supplied for operating the blowthrough a valve block, indicated generally at D, through tubes which extend between the ing a handle to the' block.

said block and head, there bethe pipes which the head,

cutting oxygen, preheating oxygen and combustible gas, respectively, to

appropriate passages F', provided therefor in the struction as thus known in the art.

G and H', respectively, head. The general confar outlined, is old and well The supply of cutting oxygen to cutting tools,

-be moved toward the handle objects in and' (ci. 15S-27.4)

such as blowpipes, is usually controlled by a valve of the plunger type which is operated by a lever arranged in proximity to the handle and adapted to be grasped by the operator, together with the handle, so that, by closing the hand, the lever will and thereby open the valve. This mode of operating the valve is attended with the disadvantage that it is dicult to control the ilow of cutting oxygen accurately, not only for the purpose of cutting a particular piece of metal with a uniform flow of oxygen and with a uniform rate of cutting, but also to enable the rate of ow of the oxygen to be varied accurately to accommodate varying thicknesses oi metal as well as variations in the character of the metal which is being cut. A further disadvantage is that, unless a lock is provided for retaining the lever in valve-opening position, added strain is imposed upon the operator through the necessity for holding the lever in such position. To lock a lever-actuated spring-pressed valve in open position requires an additional locking mechanism, which imposes upon the operator the task of unlocking the same should the heat be lost during the cutting operation.

A further disadvantage in the use of valves of the plunger type is that, because of the materials used for the seating portions of said valves, they have proved inefficient and' objectionable in use. Where both of the seating portions are made of metal in valves of the plunger type, the valves invariably leak after a short period of operation. Where rubber or rubber composition is used for one or both of the seating portions, in the case of backire/the rubber or rubber composition is completely destroyed. In addition to the leakage which develops where both seating portions of the valve are made of metal, there is a further liability to leakage, due to the fact that the rod or stem which is connected with the valve and which is engaged by the lever to unseat the valve against spring-pressure extends through packing which wears rapidly; and the fact that the packing for this valve stem or rod is located within the valve block renders the parts difficult of access, with corresponding diiculty in eiecting repairs. Finally, with a plunger type of valve, it is diicult to regulate the flow of cutting oxygen between the full-open and the full-closed position of the valve. I obviate the foregoing objections by the valve construction shown herein, and more particularly in Figs. 1, 2 and 3.

Referring more particularly to Fig. 3, it will be seen that a valve block J is inserted between the n sections of the pipe F which conducts cutting gas 110 to the head A, this valve block having internally threaded connections J and J2 for the ends of the sections of the pipe F, which threaded connections are in turn connected by a passage which comprises an upwardly extending port J3 communicating at one end withthe connection J and merging at its upper end with an annular chamber J4, a port J5 extending from the said chamber, and a port J6 leading from the last-mentioned port to the connection J2.

The valve block, as will be noted, is located in front of the front end of the handle E and in proximity thereto, as well as in vertical alignment with the tube F. The block is provided with a bore J7 extending rearwardly from the port J5 and including the chamber J4. This bore is internally threaded for the reception of a thread K on the valve stem K, the said stem being provided at its front end with a frusto-conical end K2 constituting a valve which cooperates' with the valve seat J2 provided between the chamber J4 and port J5. The stem extends through a washer L and compressible packing L', which are forced against an annular seat J9 in the bore by a threaded plug L2 which surrounds the valve stem and which is threaded into the outer enlarged end of the bore. At its extreme outer end, the valve stem K tapers and is provided with a cross bar K2, said cross bar having a tapered opening K4 therethrough whereby it is adjustably secured upon the tapered end of the valve K by means of a screw K5. The cross bar is located adjacent to the front of the handle E in a convenient position to be manipulated by the thumb of the operator.

It will be noted that the thread J'I is a triple lead thread, which renders the valve quick acting, so that it may be opened and closed by a partial rotation of the valve stem in the appropriate direction. It will be noted further that thevalve comprises metallic seating portions, thus obviating any danger of destruction, due to backfire. It will be noted further that the valve is positive in its action; that it can be adjusted instantaneously to accommodate metal of varying thickness; that it contains no spring which is liable to deterioration; that the controlling member rotates, instead of reciprocates, which enables the packing to wear for a much longer time; that the flow of gas can be accurately controlled; that the valve may be seated without the use of strong pressure; and that the valve may be set and left in any desired position without the necessity for supplemental locking or holding devices. The cross bar K3 is secured upon the valve stem K by the screw K5.

The valve block D is provided with the threaded connections D" and D2 for the rubber hose usually employed and which hose conducts the oxygen and combustible gas to appropriate passages in the block. By reference to Figs. 2 and 4, it will be seen that oxygen is supplied through the connection D2 to a passage D2, whence it iiows through a port D4 to a connection for the pipe F, and that it also flows from the port D3 through a` downwardly and outwardly inclined port D5 to a chamber D6 and thence through a port D7 to the connection for the tube G. The delivery of the oxygen from the port D5 to the chamber D8 is controlled by a valve comprising a stem M having a frusta-conical valve M at one end thereof cooperating with the annular valve seat Da at the junction o1' the port D5 with the chamber D2. The valve stem M passes through suitable stufling boxes (not shown) closed by a retaining nut M2, and the outer end of the stern is provided with a knurled grip M3.

It will be noted further that combustible gas is supplied through the connection D to a port D9 whence it is delivered through a downwardly and outwardly inclined port D1o to a chamber D11 and thence by a port D12 to the connection for the pipe H. The delivery of the combustible gas from the port D1J to the chamber D11 is controlled by a valve comprising a stem N having at its inner end a frusto-conical valve N' which cooperates with a valve seat D12 between the said chamber and port. extends through a stuing box (not shown) which is closed at its outer end by a retaining nut N2; the stem is provided at its outer end with a knurled grip N2.

Assuming the pipe to be in the position shown in Fig. 2, the valve stems M and N extend downwardly and outwardly with respect to an axial vertical plane which extends through the center of the passages F', G and H' provided in the head for the oxygen and combustible gas. Because of this arrangement of the valve stems, should the operator lay the pipe down without turning off the gas, the flame will be directed upwardly away from the supporting surface, and any danger of injuring or igniting such surface by the ilame will be prevented. Due to the arrangement of the Valve stems this result will be accomplished whether the torch be turned on one side or the other; and due to the arrangement of the valve K and its mounting J, the torch may be operated by either the right hand or the left hand. l

In assembling the grips M3 and N3 upon the valve stems M and N respectively, the outer ends of the stems and the bores in the grips are broached,` after which the stems and grips are subjected to heavy pressure which freezes the grips onto the stems.

Reference has been made hereinbefore to the tip construction and the manner of mounting the same and of supplying the gases thereto. Details of such construction and mounting are shown in Fig. 5, wherein the lower end of the blowpipe head is shown as provided with a bore A extending upwardly thereinto from the bottom of the front end thereof, the upper end of this bore being internally threaded, as shown at A2, the lower part of the passage F extending vertically from the center of such bore.

The tip B has a tapered lower end B' above which it is provided with an angular portion B2 (preferably hexagonal) and above the portion B2 with the cylindrical portion B2 extending upwardly within thevbore A. Above such cylindrical portion, the tip is provided with a circumferential groove B4 forming an annular chamber O with the surrounding portion of the bore A; and above such groove, the tip is provided with an external thread B5, adapted to mesh with the thread A2. The upper end of the tip consists of a Areduced extension B6 having a rounded seat at B7 adapted to engage a tapered seat F2 at the bottom of the passage F. A chamber P is provided between the extension B6 and the interior of the threaded portion A2 of the bore A and above the annular shoulder B8 at the base of such extension.

'Ihe tip isl provided with a central bore Q for cutting oxygen, the bore being of increasing crosssectional area from the bottom tothe top thereof and communicating at its upper end with the This valve stem also reaches bottom of the bore F. The tip is also provided with smaller bores R which extend from the bottom thereof through the shoulder B8, whereby the upper ends of these bores communicate with the chamber P. The bores R converge from the tops thereof toward the central bore Q at the bottom thereof. A substantially vertical passage R connects each bore R with the annular chamber O.

Preheating oxygen from the pipe G and passage G is delivered into the chamber P by a substantially vertical port G2; and combustible gas from the pipe H is delivered from the passage H to the chamber O by an inclined port H2.

The tip is provided with a double-tapered sealing gasket S fitting snugly the cylindrical part B3 thereof. After the tip has been screwed home within the bore A', the retaining nut C is applied thereto, being threaded upon the lower end of the head. By setting up this nut, the upper tapered end of the sealing gasket is wedged into the joint between the tip and the bottom of the bore A and the lower tapered end is wedged into the joint between the tip and the flange C of the nut. y

Because of the manner of constructing and. mounting the tip, leakage between the tip and the head will be prevented; and the oxygen and combustible gases will be delivered in a most effective manner to the bores provided therefor in the Having thus described my invention, what l claim is:

1. A blowpipe comprising in combination a head having a bore extending upwardly thereinto from the lower end thereof, there being a passage for cutting oxygen extending from the upper end of said bore and the upper portion of the said bore being threaded, with a tapered seat provided between such threaded portion and the lower end of the said passage, a tip having a threaded upper portion adapted to engage the thread within the bore `,and having a reduced extension adapted to engage the said seat, there being an annular shoulder provided between the threaded portion of the tip and the said extension and an annular chamber formed between the shoulder and the extension and the upper portion of the bore, the said tip having, below the threadl ed portion thereof, a groove therearound forming an annular chamber with the inner wall of the said bore, said head having a passage for preheating oxygen and a passage for combustible gas, one of said passages communicating with the first mentioned chamber and the other of said passages communicating with the other of said chambers, the tip having a central bore therethrough communicating at its upper end with the rst mentioned passage, and bores for preheating mixture grouped about the central bore and extending from the bottom ofthe tip through the said shoulder, the said tip having a passage extending from each of the last mentioned bores to the second annular chamber, the portion of said tip below the groove thereof fitting closely within the bore of said head.

2.A blowpipe comprising a head having a bore projecting upwardly thereinto from the lower end thereof and at substantially right angles to the longitudinal axis of said head and a passage for cutting oxygen extending upwardly from said bore and thence rearwardly and in the direction of the longitudinal axis of said head to the end of said head, the said head having a bore for preheating oxygen extending substantially parallel with and arranged below the first mentioned passage and a passage for combustible gas below I `and arranged substantially parallel with the second passage, a tip detachably mounted in the said bore and having a central bore therethrough for cutting oxygen and bores for preheating mixture grouped about the central bore, there being a port for delivering oxygen from the second passage toa chamber with which the upper ends of the said bores communicate, the port extending in substantially the same direction as the said bores, the said tip also having passages arranged below the tops of the preheating-mixture bores and extending outwardly and upwardly therefrom to anv annular chamber formed about the said tip and there being a port extending substantially in the direction of the last mentioned bores for delivering gas from the third passage to the said chamber, and means for securing the said tip within the first mentioned bore.- 3. The combination, with a blowpipe head having a bore extending upwardly thereinto from the lower end thereof, the upper portion ofthe said bore being threaded, of an integral tip adapted to t within said bore and having a threaded upper portion adapted to engage the thread in the said bore, the said tip having a cylindrical surface below the threaded portion thereof adapted to fit the interior of the lower part of the bore and to project below such portion of the bore, a retaining `and sealing nut threaded on the lower portion of the head, surrounding the bore therein, and having an inwardly directed flange adapted to bear against the cylindrical portion of the tip below 'such head bore, a gasket mounted on the cylindrical portion of the tip, below the said head, the said gasket having a wedge-shaped upper edge and a wedge-shaped lower edge, the said edges being adapted to be forced respectively into the joint between the tip and the bottom of the head bore and into the joint between the tip and the top of the retaining nut flange. 4. The combination, with a blowpipe head having a bore extending upwardly thereinto from the lower end thereof, the upper portion of the said bore being threaded, of a tip adapted to t within said bore and having a threaded upper portion adapted to engage the thread in the said bore, the said tip having a cylindrical surface below the threaded portion thereof adapted to flt the interior of the lower part of the bore and to project below such portion of the bore, a retaining nut threaded on the lower portion of the head, surrounding the bore therein, and having an inwardly directed flange adapted to bear against the cylindrical portion of the tip below such head bore, a gasket mounted on the cylindrical portion of the tip, below the said head, the

^ said gasket being substantially v-shaped in section whereby it is provided with a wedge-shaped,

upper edge and a wedge-shaped lower edge, the said edges being adapted to be forced respectively into the joint between the tip and the bottom of the headbore and into the joint between the tip and the top of the retaining nut flange, the tip body being/provided with surfaces below the nut flange for the reception of a wrench.

5-. A blowpipe comprising in combination a head, pipes for combustible gas and cutting and preheatingy oxygen leading from said head, a handle surrounding the said pipes, and valve mechanism in the cutting oxygen pipe for controlling the flow of oxygen through said pipe, the said mechanism comprising a valve block having a passage therethrough, the said block having an extension provided with a bore intersecting said passage and forming a valve seat within said passage, the said bore having a plural lead thread therein, a valve comprising a valve stem having a plural lead thread thereon meshing with the thread in the bore, and having at its front end a tapered valve body arranged to engage the said seat, packing means in the outer portion of said bore and surrounding the said valve stem, a cross bar on the outer end of the valve stem arranged at convenient location with reference to the said handle, and means for adjustably securing the cross bar on the outer end of the valve stem.

6. A blowpipe comprising in combination a head, pipes for cutting gas and preheating oxygen leading from said head, a pipe for cutting oxygen also leading from said head and comprising pipe sections and a valve block connecting said sections and having a passage therethrough communicating with said sections, a handle surrounding the first two pipes and the rear section of the third pipe, the said valve block having a threaded bore communicating with said passage and forming a valve seat at its junction therewith and extending from the said passage toward said handle, and a valve stem threaded in said bore and having at its front end a valve cooperating with said seat, and a cross bar on the rear end of said stem.

7. A blowpipe comprising in combination a head, pipes for cutting gas and preheating oxygen leading from said head, a pipe for cutting oxygen also leading from said head and comprising pipe sections and a valve block connecting said sections, a handle surrounding the rst two pipes and the rear section of the third pipe, the said valve block having a passage therethrough communicating with said pipe sections, the said passage comprising a pair of passage sections with a chamber therebetween providing a valve seat with the end of one of said passage sections, the said block having a bore extending from said chamber toward said handle, and a valve stem threaded in said bore and having at its inner end a valve cooperating with said seat, and a cross bar on the outer end of said stem.

` LORN CAMPBELL, JR. 

